Prospective evaluation of a new Aspergillus IgG EIA kit for the diagnosis of chronic and allergic pulmonary aspergillosis

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Independent evolution of shape and motility allows evolutionary flexibility in Firmicutes bacteria

Functional morphological adaptation is an implicit assumption across many ecological studies. However, despite a few pioneering attempts to link bacterial form and function, functional morphology is largely unstudied in prokaryotes. One intriguing candidate for analysis is bacterial shape, as multiple lines of theory indicate that cell shape and motility should be strongly correlated. Here we present a large-scale use of modern phylogenetic comparative methods to explore this relationship across 325 species of the phylum Firmicutes. In contrast to clear predictions from theory, we show that cell shape and motility are not coupled, and that transitions to and from flagellar motility are common and strongly associated with lifestyle (free-living or host-associated). We find no association between shape and lifestyle, and contrary to recent evidence, no indication that shape is associated with pathogenicity. Our results suggest that the independent evolution of shape and motility in this group might allow a greater evolutionary flexibility

Genetic differentiation of European grayling (Thymallus thymallus) populations in Serbia, based on mitochondrial and nuclear DNA analyses

<p>Abstract</p> <p>Background</p> <p>The structure and diversity of grayling (<it>Thymallus thymallus</it>) populations have been well studied in most of its native habitat; however the southernmost populations of the Balkan Peninsula remain largely unexplored. The purpose of this study was to assess the genetic diversity of Serbian grayling populations, detect the impact of stocking and provide guidelines for conservation and management.</p> <p>Methods</p> <p>Eighty grayling individuals were collected from four rivers (Ibar, Lim, Drina and Rzav). The mitochondrial DNA control region (CR; 595 bp of the 3'end and 74 bp of flanking tRNA) and the ATP6 gene (630 bp fragment) were sequenced for 20 individuals (five from each locality). In addition, all individuals were genotyped with 12 microsatellite loci. The diversity and structure of the populations as well as the recent and ancient population declines were studied using specialized software.</p> <p>Results</p> <p>We detected three new haplotypes in the mtDNA CR and four haplotypes in the ATP6 gene of which three had not been described before. Previously, one CR haplotype and two ATP6 gene haplotypes had been identified as allochthonous, originating from Slovenia. Reconstruction of phylogenetic relations placed the remaining two CR haplotypes from the River Danube drainage of Serbia into a new clade, which is related to the previously described sister Slovenian clade. These two clades form a new Balkan clade. Microsatellite marker analysis showed that all four populations are genetically distinct from each other without any sign of intra-population structure, although stocking of the most diverse population (Drina River) was confirmed by mtDNA analysis. Recent and historical population declines of Serbian grayling do not differ from those of other European populations.</p> <p>Conclusions</p> <p>Our study shows that (1) the Ibar, Lim and Drina Rivers grayling populations are genetically distinct from populations outside of Serbia and thus should be managed as native populations in spite of some introgression in the Drina River population and (2) the Rzav River population is not appropriate for further stocking activities since it originates from stocked Slovenian grayling. However, the Rzav River population does not represent an immediate danger to other populations because it is physically isolated from these.</p

Conserved natural IgM antibodies mediate innate and adaptive immunity against the opportunistic fungus Pneumocystis murina

Natural IgM antibodies in diverse species recognize conserved carbohydrates in fungal cell walls and influence early host defense against Pneumocystis in mice

Direct Measurements of Colloidal Solvophoresis under Imposed Solvent and Solute Gradients

We describe a microfluidic system that enables direct visualization and measurement of diffusiophoretic migration of colloids in response to imposed solution gradients. Such measurements have proven difficult or impossible in macroscopic systems due to difficulties in establishing solution gradients that are sufficiently strong yet hydrodynamically stable. We validate the system with measurements of the concentration-dependent diffusiophoretic mobility of polystyrene colloids in NaCl gradients, confirming that diffusiophoretic migration velocities are proportional to gradients in the logarithm of electrolyte concentration. We then perform the first direct measurement of the concentration-dependent "solvophoretic" mobility of colloids in ethanol-water gradients, whose dependence on concentration and gradient strength was not known either theoretically or experimentally, but which our measurements reveal to be proportional to the gradient in the logarithm of ethanol mole fraction. Finally, we examine solvophoretic migration under a variety of qualitatively distinct chemical gradients, including solvents that are miscible or have finite solubility with water, an electrolyte for which diffusiophoresis proceeds down concentration gradients (unlike for most electrolytes), and a nonelectrolyte (sugar). Our technique enables the direct characterization of diffusiophoretic mobilities of various colloids under various solvent and solute gradients, analogous to the electrophoretic ζ-potential measurements that are routinely used to characterize suspensions. We anticipate that such measurements will provide the feedback required to test and develop theories for solvophoretic and diffusiophoretic migration and ultimately to the conceptual design and engineering of particles that respond in a desired way to their chemical environments

Mechanomicrobiology: how bacteria sense and respond to forces

Microbiology and biophysics are converging to advance our understanding of the mechanobiology of microorganisms. In this Review, Dufrene and Persat discuss the physical forces that bacteria experience in their natural environments and the structures that transmit these forces to a cell. Furthermore, they explore bacterial phenotypes influenced by mechanical inputs, including adhesion, motility and biofilm formation.Microorganisms have evolved to thrive in virtually any terrestrial and marine environment, exposing them to various mechanical cues mainly generated by fluid flow and pressure as well as surface contact. Cellular components enable bacteria to sense and respond to physical cues to optimize their function, ultimately improving bacterial fitness. Owing to newly developed biophysical techniques, we are now starting to appreciate the breadth of bacterial phenotypes influenced by mechanical inputs: adhesion, motility, biofilm formation and pathogenicity. In this Review, we discuss how microbiology and biophysics are converging to advance our understanding of the mechanobiology of microorganisms. We first review the various physical forces that bacteria experience in their natural environments and describe the structures that transmit these forces to a cell. We then discuss how forces can provide feedback to enhance adhesion and motility and how they can be transduced by dedicated cellular machinery to regulate diverse phenotypes. Finally, we provide a perspective on how mechanics influence biofilm spatial organization and homeostasis

Interdiffusion and magnetism of the Co/Rh interface studied by magnetization induced second harmonic generation

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